/* Reset */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f0f0f0;
  color: #222;
  margin: 0;
  padding: 20px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark {
  background-color: #121212;
  color: #eee;
}

.container {
  max-width: 600px;
  margin: 0 auto;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  margin: 0;
  font-weight: 700;
}

#modeToggle {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: inherit;
  transition: transform 0.3s ease;
}

#modeToggle:hover {
  transform: rotate(20deg);
}

.input-group {
  margin: 20px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.input-group input[type="text"],
.input-group input[type="datetime-local"] {
  flex: 1;
  padding: 10px;
  font-size: 16px;
  border: 2px solid #ccc;
  border-radius: 6px;
  transition: border-color 0.3s ease;
}

.input-group input[type="text"]:focus,
.input-group input[type="datetime-local"]:focus {
  outline: none;
  border-color: #007bff;
}

.input-group button {
  padding: 10px 15px;
  font-size: 16px;
  border: none;
  background-color: #007bff;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.3s ease;
  user-select: none;
}

.input-group button:hover {
  background-color: #0056b3;
}

.clear-btn {
  background-color: #dc3545;
}

.clear-btn:hover {
  background-color: #a71d2a;
}

ul#taskList {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul#taskList li.task {
  background-color: white;
  border-radius: 6px;
  margin-bottom: 10px;
  padding: 12px 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 1px 6px rgba(0,0,0,0.1);
  transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark ul#taskList li.task {
  background-color: #222;
  color: #eee;
}

ul#taskList li.task.completed {
  text-decoration: line-through;
  opacity: 0.6;
}

ul#taskList li.task span {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-width: 75%;
  word-break: break-word;
}

ul#taskList li.task span small {
  font-size: 12px;
  color: #666;
}

body.dark ul#taskList li.task span small {
  color: #bbb;
}

.tag {
  background-color: #007bff;
  color: white;
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 12px;
  display: inline-block;
  margin-top: 3px;
}

body.dark .tag {
  background-color: #3399ff;
}

ul#taskList li.task span button {
  border: none;
  background: none;
  font-size: 18px;
  margin-left: 10px;
  cursor: pointer;
  transition: color 0.3s ease;
}

ul#taskList li.task span button:hover {
  color: #007bff;
}

.next-task {
  margin-top: 30px;
  padding: 15px;
  border: 2px solid #007bff;
  border-radius: 8px;
  background-color: #e7f1ff;
  color: #003366;
  user-select: none;
}

body.dark .next-task {
  background-color: #004080;
  color: #cce6ff;
}

/* Animations */
ul#taskList li.task {
  animation: fadeIn 0.5s ease forwards;
}

@keyframes fadeIn {
  from {opacity: 0; transform: translateY(-10px);}
  to {opacity: 1; transform: translateY(0);}
}